<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>作用域面试题</title>
</head>
<body>
    <script>


    /* 
       注意函数的调用是基于方法栈的调用 而不是把另一个函数的代码复制粘贴到当前位置
    */
    var x = 10;
        function fn() {
            console.log(x);
        }

        function show(f) {
            var x = 20;
            f();
        }
      show(fn);//10




            var fn = function () {
                console.log(fn)
        }
            fn()

            var obj = {
                fn2: function () {
                 console.log(fn2)//is not defined 不会找自己的fn2
                }
        }
                obj.fn2()

    </script>
</body>
</html>